As a related art hydraulic control valve used for the valve timing control device of the internal combustion engine, various kinds of hydraulic control valves have been provided. One of such hydraulic control valves has been disclosed in the following Patent Document 1.
As a brief explanation, the hydraulic control valve has a cylindrical valve body serving as a cam bolt that fixes a vane rotor to an axial direction one end portion of a camshaft, a cylindrical sleeve accommodated and fixed inside the valve body, a spool valve provided slidably along an axial direction inside the sleeve and a solenoid pressing the spool valve to the other direction against a spring force of a valve spring that forces the spool valve to one direction.
The valve body has, at a peripheral wall thereof, a plurality of ports that penetrate the peripheral wall in a radial direction and communicate with advance hydraulic chambers and retard hydraulic chambers etc. On the other hand, the sleeve has, on an outer peripheral surface thereof, a plurality of communication passages formed along an axial direction of the sleeve. Further, a plurality of communication holes are formed at an axial direction end portions of the communication passages and on a peripheral wall of the outer peripheral surface of the sleeve.
The spool valve slides in the axial direction by a control current that is outputted to the solenoid from a control unit, and controls opening areas of each communication hole and each communication passage of the sleeve through oil holes formed on a peripheral surface of the spool valve.
By moving the spool valve in the axial direction in accordance with an engine operating condition, the communication passage and the port properly communicate with each other, and oil pumped out from an oil pump is selectively supplied to and discharged from advance hydraulic chambers and retard hydraulic chambers of the vane rotor, then a relative rotation phase of the camshaft with respect to a crankshaft is varied.